The mean heat transfer coefficient on a small sphere of diameter d0 with chloroform flowing over it is to be determined. This involves a number of experiments with water on a sphere with a diameter...

The mean heat transfer coefficient on a small sphere of diameter d0 with chloroform flowing over it is to be determined. This involves a number of experiments with water on a sphere with a diameter ten times larger.

a) At what temperature do the experiments have to be run, if the mean temperature of the chloroform is T0 = 293 K?

b) The main interest is in heat transfer coefficients in the chloroform for flow velocities in the region 0.2 m/s ≤ w_α
≤ 2 m/s. Over what range of velocities do the experiments with water have to be carried out?

c) In the model experiments a mean heat transfer coefficient of αM = 250W/m²K is found for a certain state. How big is the mean heat transfer coefficient on the sphere with the chloroform flowing over it for the same Reynolds and Prandtl numbers?

The following material data for chloroform at T₀
= 293 K are known: ν = 0.383·10⁻⁶
m²/s, λ = 0.121W/Km, P r = 4.5. The properties for water can be read off the graph, Fig. 3.56.